Abstract

A study has been made of the toxicity for dogs of a protein-free preparation of the bactericidal substance described by Dubos when injected by the intravenous route. Seven of the 8 animals which received 0.4 mg/kg or more daily died as a result of the injections, and in 6 of these death occurred before the course of 10 daily injections was completed. All animals receiving 0.3 mg/kg or more snowed well-marked acute or chronic changes in the liver, spleen, kidneys, heart and lungs. Animals which received daily 0.2 mg/kg or less for 10 days showed only minor evidence of toxicity.